<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    div{width: 200px;
    height: 200px;
border-top: 10px;
border-top-style: dashed;
border-top-color: yellow;}    
.box{width: 200px;
    height: 200px;
    border-width: 20px;
    border-style: solid;
    border-color: blue;
}

    </style>
</head>
<body><div>
</div>
<br>
<div class="box"></div>
    
</body>
</html>